CVE-2026-66033

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

UBUNTU-CVE-2026-66033

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

CVE-2026-66035 libssh2 Heap Buffer Overflow via ETM Cipher Negotiation

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

CVE-2026-66035 libssh2 Heap Buffer Overflow via ETM Cipher Negotiation

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

CVE-2026-66035 libssh2 Heap Buffer Overflow via ETM Cipher Negotiation

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

EUVD-2026-48722

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

CVE-2026-66035

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

CVE-2026-66035

CVE-2026-66035 affects libssh2 up to 1.11.1 and was fixed in commit 42e33d8. The vulnerability is a pre-authentication heap buffer overflow in the Encrypt-then-MAC (ETM) cipher negotiation path. In libssh2’s fullpacket() implemented under src/transport.c, the ETM code path allocates a buffer of p...

CVE-2026-66033 libssh2 Integer Underflow DoS via AES-GCM Cipher Negotiation

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

CVE-2026-66033 libssh2 Integer Underflow DoS via AES-GCM Cipher Negotiation

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

EUVD-2026-48720

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

CVE-2026-66033

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

CVE-2026-66033 libssh2 Integer Underflow DoS via AES-GCM Cipher Negotiation

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

CVE-2026-66033

CVE-2026-66033 affects libssh2 up to 1.11.1. A pre-authentication integer underflow in the ssh2_cipher_crypt() function (src/openssl.c) allows a malicious SSH server to crash a connecting client during handshake by negotiating AES-GCM ciphers. The underflow (blocksize − aadlen − taglen) can trigg...

PT-2026-64382

Name of the Vulnerable Software and Affected Versions libssh2 versions prior to 1.11.1 Description A pre-authentication heap buffer overflow occurs during Encrypt-then-MAC ETM cipher negotiation. A malicious SSH server can corrupt heap metadata in a connecting client by sending a packet where the...

PT-2026-64380

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2 cipher crypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploi...

CVE-2026-16606 Unauthenticated remote code execution (pre-auth RCE) vulnerability in openFT for Linux and Oracle Solaris

A vulnerability in Fujitsu Software Linux openFT and Fujitsu Software Oracle Solaris openFT before version 12.1D00 allows for unauthenticated remote code execution pre-auth RCE on GNU/Linux or Oracle Solaris. The Fsas Technologies PSIRT obtained that intelligence internally and covers the CVE...

Critical ServiceNow AI Platform Flaw Exploited for Unauthenticated Code Execution

Threat actors are now exploiting a recently disclosed critical security flaw impacting ServiceNow AI Platform, according to Defused Cyber. In a post shared on X, the threat intelligence firm said it's observing in-the-wild exploitation of CVE-2026-6875 CVSS score: 9.5, a sandbox escape...

MGASA-2026-0273 Updated libssh2 packages fix security vulnerabilities

The updated packages fix security vulnerabilities: Heap Buffer Over-read via sftpsymlink in sftp.c. CVE-2025-15661 libssh2 userauth.c userauthpassword integer overflow. CVE-2026-7598 Pre-Authentication DoS via SSHMSGEXTINFO Handler. CVE-2026-55199 Out-of-Bounds Write via Unchecked packetlength in...

Updated libssh2 packages fix security vulnerabilities

The updated packages fix security vulnerabilities: Heap Buffer Over-read via sftpsymlink in sftp.c. CVE-2025-15661 libssh2 userauth.c userauthpassword integer overflow. CVE-2026-7598 Pre-Authentication DoS via SSHMSGEXTINFO Handler. CVE-2026-55199 Out-of-Bounds Write via Unchecked packetlength in...